expi;i;i.mi:ntai. staikins — imu'okt F(ii; l^70. 



•JO!) 



green and more vi^orons t^rowtli tliiin tin; others. After about 

 two months tlie pots with undissolved phosjiliates l)eLjan to turn 

 yellow in the lower leaves, whieh soon Ix'^an to shrivel up, 

 showinf,' that the nourishment in them was licino- reabsorbed ami 

 made use of further up the plant where the growtli was ji^oing 

 on. This is a sure sij^ii of defective nutrition, for not until the 

 su])])ly at the roots is inade([uate does the ])laiit bej^in to use up 

 the reserve of nourishment contaiiuMl in tlie less useful parts of 

 its own organism. 'I'hose which received dissolved manures and 

 increased amounts of manure did not show tliat tendency till 

 some weeks later. As tiie experiment proceeded, the dillerences 

 exhibited by the various pots were very striking. From the ten 

 seeds there grew u]» in some cases u])wards of thirty straws, 

 while in others the nundter was limited to the original ten, and 

 in a few instances one of the ten did not mature. In height and 

 calibre of straw, also, some plots were double others. The cro]) 

 was allowed to stand until it was dead ripe, and it was cut 

 down on lOtli Septend)er. The straw was cut about an inch 

 from the earth, and the grain was carefully removed with the 

 hand. It was thereafter taken to the lal)oratorv, dried at lOO'^C. 

 and weighed. The nund)er of barley corns in each was counted, 

 and the dried straws were also counted and weighed. 



A glance at the mnnlters on the above table show tliat the soil 

 selected for the experiments was well-ada]»ted to exhibit the 

 efficacy of the manures api)lied. The nund)er of grains range 

 from about 100 to u[)wards of 600, and the weights of these 

 fihow a corres]»on(liiig difference. The nundier of straws range 

 from lune to more than thirty, and their weights difter still more 

 widely. On comparing the returns of the first ten plots we 

 obtain the following nundiers: — 



1'hosphate Plots. 



